1. Field of the Invention
The invention relates to perfume compositions, wherein different scent notes are successively released (scent sequence).
2. Description of the Related Art
It is known that perfume preparations with differing volatilities after opening a perfume flask release a so-called head note followed by a heart note and finally a fond note. Generally, the head note is determined by low boiling alcohols such as ethanol, while an extended fond note can be accomplished, for example, by less volatile oils or bonding to a carrier with the assistance of high boiling solvents.
In order to influence the volatility of perfume compositions and to achieve an effectiveness period being as long as possible on the skin of the user, among other methods the enclosure of perfumes in capsules has been applied. For example, EP 838216 suggests an encapsulation using high-bloom gelatine capsules wherein the aromatic substance is provided encapsulated together with a volatile solvent and a non-volatile co-solvent. Further, known perfume compositions comprise cyclodextrines (e.g. from EP 0013688) or cyclodextrines in an aqueous carrier, moisture-keeping agents and agents active on the surface (e.g. from WO 98/56341).
It is an object of the invention to provide a perfume composition wherein, when applied onto the skin, different scent notes are released successively but nearly completely isolated from each other.
According to the invention, the perfume composition comprises
a) at least a first perfume ingredient consisting of at least a first and a second aromatic substance in the absence of alcohol, wherein the aromatic substances are contained in microcapsules, and
b) at least a second perfume ingredient consisting of at least a third and a fourth aromatic substance in the absence of alcohol, wherein the aromatic substances are contained in microcapsules, and
c) a cosmetic gel in which the first and the second perfume ingredients are distributed.
In an advantageous embodiment of the invention, the microcapsules of the first perfume ingredient or the second perfume ingredient contain, apart from the aromatic substances, lamellar liquid crystals or mixtures of liquid crystals.
The microcapsules are manufactured using common methods, wherein a liquid is used as a suspension medium for the microcapsules and wherein the emulsification/dispersion of two or more phases non-miscible with each other is performed. These methods include interfacial polymerisation, in-situ polymerisation, solvent evaporation, gelatinisation, pressure extrusion, polymer-polymer incompatibility, and simple and complex coacervation. The three last methods are preferred.
During coacervation, the individual droplets of the wall polymer settle on the surfaces of a core material, wherein it is essential that the core is insoluble in the solvent of the polymer material, and the wall polymer is hardly able to distribute in the core material. After completely covering the surface of the core material with microdroplets followed by coalescence the coacervates form a wall around the core material. If necessary, this wall may be hardened in addition. (for coacervation, see for instance Hallcrest, Handbook of Thermochrome Liquid Crystal Technology (1991), pp. 11-12).
If liquid crystals are selected as core material, the process described above may also be performed in such a manner that the lamellar liquid crystals are brought into contact with the respective aromatic substances and are transformed into coacervates. Different wall thicknesses can be accomplished using known methods.
The capsules formed may have a diameter ranging from 5-10 xcexcm up to 2000 xcexcm. In case of diameters below 500 xcexcm, the wall thicknesses range from 5 to 20 xcexcm.
In a preferred embodiment the wall thicknesses of the micro-capsules range from 100 to 2000 nm.
In a further preferred embodiment three different perfume ingredients are encapsulated in the microcapsules. The first perfume ingredient comprises two orange scent substances, the second perfume ingredient two vanilla scent substances, and the third perfume ingredient two rose scent substances.
Usable liquid crystals include cholesteric substances such as cholesterol, cholesterol ester, phytosterols, particularly B-sitosterol and camposterol, phytosterol ester, dihydrosterol ester, non-specific sterol derivatives or else mixtures of cholesterol with 2-acetaminoalkane-1,3-diolene and 2-acylami-noalkane-1,3-diolen as well as chiralically nematic substances such as (2-methyl butyl)phenyl-4-alkyl(oxy)benzoate.
Examples of aromatic substances in the perfume compositions according to the invention include: ambre, anekole C10H12O, angelica root oil, artemisia oil, basil oil, rose oil, lavender oil, bay oil, benzaldehyde C7H6O, bergamot oil, benzyl acetate C9H10O2, camphor C10H17O, calamus oil, carrot oil, camomile oil, citronella oil, couramine C9H6O2, cyprene oil, dihydromyrcenol C10H20O, jasmine, mimosa, muscone C16H30O, narcissus, orange oil, rose oxide C10H18O, sandelwood oil, vanilla C8H8O3. A wide variety of other aromatic substances can be used, in particular variants of individual aromatic substances having similar scent nuances.
It is an essential characteristic of the invention that at least two aromatic substances form each one of several perfume ingredients within the perfume composition according to the invention and that no light volatile solvent, i.e. no alcohol, is added to these perfume ingredients.
Preferably, the first, second, third and fourth aromatic sub-stances have a different volatility, i.e. a different boiling point.
It is further preferable that the volatility increases from the first to the fourth and, if applicable, any further aromatic substance.
In another embodiment of the invention, the wall thickness of the microcapsules differs among the individual perfume ingredients and preferably increases from the first perfume ingredient to the second perfume ingredient and, if applicable, to any further perfume ingredient. This allows the capsule walls of the microcapsules to break open at different points in time.
For example, the wall thickness of the capsules containing the first perfume ingredient may be 100 to 200 nm, that of the capsules containing the second perfume ingredient 400 to 500 nm and that of the capsules containing the third perfume ingredient may exceed 500 nm.
The invention allows to apply onto the skin different scent notes consisting of at least two different aromatic substances in a micro-encapsulated form, to destroy during the soft initial application of the gel onto the skin the capsule walls of the capsules containing a first perfume ingredient and thus to release the mixture of the first and second aromatic substances as the xe2x80x9chead note xe2x80x9d of the perfume.
A little later, a second scent note is released in the form of the mixture of the at least third and fourth aromatic substances with no essential mixed scent phase occurring between both aromatic substances.
If applicable, a third or further scent note is released in the form of a mixture of at least a fifth and a sixth and, if applicable, further aromatic substances (mixtures), each with no essential mixed scent phase occurring in between.
Hitherto it is unclear what causes the release of the further aromatic substances without any visible external influence and what prevents the occurrence of a mixed scent phase. It can be assumed that there is an interaction with skin proteins plus the influence of skin temperature.
In the sense of this invention, xe2x80x9cwithout an essential mixed scent phasexe2x80x9d means that a mixture of two scent notes is nearly imperceptible and, if at all, occurs for a few seconds only (e.g. 2-8 seconds).
The combination according to the invention creates a scent sequence desired by the user which up to now could not be created in this form. Although it was possible in the prior art to create a scent sequence using the adherence to the skin and different solvents with varying boiling points plus, if applicable, further additives, but firstly this always required the presence of solvents such as alcohols, and secondly, always an extended and hardly influenceable mixed scent phase occurred during which no clear scent note could be discerned.
Further, the use of liquid crystals having a lamellar phase according to the invention allows a longer binding of the aromatic substances to said phase and as a whole a delayed release of the scents.
Moreover, temperature-sensitive and thermochrome liquid crystals allow especially attractive colour effects shown by the microcapsules in the gel. This factor may be further enhanced by adjusting the viscosity degree of the gel to a higher level, e.g. above 50000 Paxc2x7s by depositing the various microcapsules punctually, helically, on discrete locations in the gel, in layers or in another distribution and keeping them at these locations. A uniform distribution may also be accomplished by intensive shaking or by distributing the microcapsules in a less viscous gel.
A preferred perfume composition according to the invention includes three perfume ingredients. The first perfume ingredient comprises two different orange scent substances, the second perfume ingredient two different vanilla scent substances, and the third perfume ingredient two different rose scent substances.
As mentioned above, a preferred embodiment of the invention includes the selection of the wall thickness of the microcapsules and the volatility of the aromatic substances in such a way that after applying the perfume composition onto the skin the aromatic substances of the first perfume ingredient are released first, followedxe2x80x94without an essential mixed scent phasexe2x80x94by the aromatic substances of the second perfume ingredient, followed by the aromatic substances of the third and, if applicable, any further perfume ingredients.
The dispersion of the perfume ingredients may be carried out in known cosmetic gels. These include carbomer, xanthane rubber, carrageenan, acacia gum, guar gum, agar-agar, alginates and tyloses, carboxymethyl cellulose, hydroxyethyl cellulose, certain polyacrylates, polyvinyl alcohol, polyvinyl pyrrolidone, silicone gels.